JPS64490B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a bulky mixed fiber yarn, and more particularly to a mixed fiber yarn consisting of a latent crimpable synthetic fiber yarn and a thermoplastic synthetic fiber yarn having different heat shrinkability from this yarn. The present invention relates to a method for producing a spun-like bulky mixed fiber yarn by treating it under specific conditions. Conventionally, synthetic fiber yarns with latent crimp properties are made by spinning two or more different polymers or the same polymers with different thermal histories into a cross section with a dorsal-ventral structure or an eccentric core-sheath structure. Composite yarns are known. Such composite yarns are generally crimped by utilizing the difference between heat shrinkage forces. The problem with latent crimp yarns made of these composite yarns is that there are still few yarns that have a strong crimp-inducing ability that causes crimp to occur in fabrics such as woven or knitted fabrics, and their uses are limited. The crimp development process is carried out in the state of the yarn. However, such composite yarns have a weak crimp ability, and cannot impart elasticity to the fabric after being made into a fabric. Furthermore, the bulkiness is insufficient, and it is not possible to impart a spun-like feel to the fabric. Further, in addition to the above-mentioned composite yarns and crimped yarns formed by twisting, different shrinkage mixed fiber yarns are known, which are a mixture of two or more types of yarns having different heat shrinkability. For example, this differential shrinkage mixed fiber yarn is used to impart bulkiness to the fabric through the difference in heat shrinkage during the heat treatment during dyeing after it is made into a fabric, but it cannot impart sufficient bulkiness to the fabric and is not suitable for spun-like fabrics. It was not possible to give it a unique texture. The present invention is intended to eliminate such conventional drawbacks, and its purpose is to provide a method for producing a spun-like bulky mixed fiber yarn having a high degree of bulk and a loop-like yarn configuration. be. In other words, the present invention provides 1.7×10 ^-4 g/
Latent crimpable synthetic fiber yarn A that develops 15 crimps/2.5 cm or more when subjected to crimping treatment for 10 minutes under the load of d, and a hot water shrinkage rate of 10% to 20%. and has a hot water shrinkage rate of 5% to 10% higher than that of the yarn A.
The gist of the present invention is a method for producing a bulky mixed fiber yarn, which is characterized in that a mixed fiber yarn consisting of a thermoplastic synthetic fiber yarn B with a larger % content is subjected to relaxation heat treatment under conditions that satisfy the following formula (1). However, OF: Relaxation rate (%) T: Heat treatment temperature (℃) 100≦T≦180 S ₁ : Hot water shrinkage rate of yarn A (%) S ₂ : Hot water shrinkage rate of yarn B (%) Below , the present invention will be explained in detail. First, in the present invention, a latent crimpable synthetic fiber yarn A is used as one yarn constituting the mixed fiber yarn, but the yarn A has two different heat shrinkability.
Composite yarn obtained by composite spinning of composite components of seeds is used. For example, any known composite yarn may be used, such as a combination of two or more different polymers, a combination of the same type of polymers with different degrees of polymerization, or a combination of the same type of polymers with different thermal histories. Preferably, various combinations of polyamide or polyester are used. Further, the structure of the composite yarn may be either a dorsal-ventral structure or an eccentric core-sheath structure. Yarn A needs to be a yarn that develops 15 crimps/2.5 cm or more when subjected to crimp development heat treatment. A yarn that develops less than 15 crimps/2.5 cm of crimps when subjected to crimp development heat treatment cannot obtain sufficient bulk. Here, crimp development heat treatment is 1.7× in boiling water.
The treatment is carried out under a load of 10 ^-4 g/d for 10 minutes. In addition, the number of crimps is a value obtained by collecting a sample subjected to the above-mentioned treatment on a filter paper and counting it under a load of 2 mg/d after air drying. Next, as the thermoplastic synthetic fiber yarn B, which is the other yarn constituting the mixed fiber yarn, a normal yarn made of a single polymer or a composite yarn similar to the yarn A can be used. The yarn B needs to have a hot water shrinkage rate in the range of 10% to 20%. If the hot water shrinkage rate of Yarn B is less than 10%, the difference in hot water shrinkage rate from Yarn A will be insufficient, making it difficult to form sufficient loops in Yarn A during the relaxation heat treatment described below. Become. On the other hand, if it exceeds 20%, the shape of the yarn obtained becomes unstable, the yarn tends to be too tight and stiff, and it is difficult to obtain a bulky texture when made into a fabric. Further, the yarn B needs to have a hot water shrinkage rate that is 5% to 10% higher than that of the yarn A. If the difference between the hot water shrinkage rate of Yarn B and the hot water shrinkage rate of Yarn A is less than 5%, the difference in hot water shrinkage rate is too small and Yarn A
loops are difficult to form, making it difficult to obtain spun-like yarns. On the other hand, if the difference between the hot water shrinkage rate of yarn B and the hot water shrinkage rate of yarn A exceeds 10%, the loop of yarn A will become too long and sag will easily occur during the relaxation heat treatment, which will be described later. In addition, there is a risk that problems may occur during unwinding from the thread winding body and contact with guides in subsequent steps. The above mixed yarn consisting of yarn A and yarn B is yarn A.
It can be obtained by mixing and yarn B using a known mixing method, but in order to sufficiently mix both yarns, it is preferable to mix them as early as possible in the yarn manufacturing process. For practical purposes, it is preferable to mix the fibers in the drawing process. It is preferable that the hot water shrinkage rate of the mixed yarn consisting of yarn A and yarn B is close to the hot water shrinkage rate of yarn B. In the present invention, the above-mentioned mixed fiber yarn is subjected to relaxation heat treatment to obtain the desired bulky mixed fiber yarn.The relaxation heat treatment conditions include relaxation rate OF (%), heat treatment temperature T (℃), mixed fiber yarn. The conditions of equation (1) above, which indicates a specific relationship between the hot water shrinkage rates S ₁ (%) and S ₂ (%) of yarn A and yarn B constituting the yarn A and yarn B, are adopted. In general, the shrinkage of fibers is affected by the heat treatment temperature; when the temperature is raised, heat shrinkage stress is generated, relaxation occurs in the high temperature range, and heat shrinkage stress decreases with temperature. Heat shrinkage stress has a maximum point, but synthetic fibers such as polyester and polyamide have a maximum point of 100 to 180.
At °C, the difference in thermal shrinkage stress due to temperature difference is gradual. Furthermore, the state of crimp development is affected not only by the heat treatment temperature but also by the tension state. In the present invention, when the mixed fiber yarn is subjected to relaxation heat treatment,
Since the heat shrinkability of yarn A and yarn B that constitute the mixed fiber yarn is different, different tension states are imparted to yarn A and yarn B, and yarn A has a small hot water shrinkage rate.
The yarn B, which has a high hot water shrinkage rate, shrinks greatly. The yarn A is crimped and spread, and is mainly arranged around the yarn B, and a loop is formed at the location where the crimp is reversed. Further, each unit of yarn A and yarn B becomes intertwined in a yarn form. Yarn B
When a composite yarn with latent crimp properties is used, the occurrence of crimp in yarn B can be suppressed by the balance between the heat shrinkage stress and the tension state during the relaxation heat treatment, but depending on the conditions, the occurrence of crimp may be suppressed slightly. Crimp develops. In the present invention, it is necessary to perform the relaxation heat treatment under the conditions shown by the above formula (1); if the relaxation rate is too small compared to the heat treatment temperature, the yarn A cannot be crimped; If the relaxation rate is too large, the slack between yarn A and yarn B will increase, and the cohesiveness of yarn A and yarn B will deteriorate, resulting in a decrease in workability during relaxation heat treatment and in the present invention. The desired yarn cannot be obtained. In addition, the heat treatment temperature is 100°~, where the thermal shrinkage stress is large and relatively stable.
The temperature is preferably 180°C, and if it is less than 100°C, the yarn A will not be able to develop sufficient crimp, and if it exceeds 180°C, the yarn A will not be able to develop sufficient crimp. Since the bulky composite mixed fiber yarn obtained by the method of the present invention is in a mixed fiber state, the single yarns are intertwined without any alternating current treatment such as interlacing, so it can be used without any problem in the subsequent process. It is something that can be provided. However, in order to create a more special yarn shape or to make it easier to handle in the post-process, it is necessary to
It is preferable to perform twisting of about 500T/M. If a yarn with latent crimpability is used as the yarn B, the latent crimpability that was suppressed during the above-mentioned relaxation heat treatment can be brought out by the heat treatment after it is made into a fabric. In addition to the bulkiness in the strip state and the loop shape, it can be made even bulkier and has improved elasticity. In the present invention, as described above, a mixed yarn consisting of a latent crimpable synthetic fiber yarn A and a thermoplastic synthetic fiber yarn B, which has a higher hot water shrinkage rate, is prepared under specific conditions. Since the relaxation heat treatment is performed, the yarn A develops crimping and the yarn B contracts, thereby making it possible to obtain a mixed fiber yarn having high bulkiness. Moreover, yarn B
Since yarn B has a higher hot water shrinkage rate than yarn A, yarn B shrinks more than yarn A, and part of the crimp of yarn A becomes a loop, making it possible to create a spun-like yarn. can. Moreover, the presence of this loop-shaped crimp makes it possible to further increase the bulkiness. In addition, in the present invention, since heat treatment is performed under low tension, the crimp fixation property is not very high, but there is no problem in practical use. A thread with fixation properties is obtained. The hot water shrinkage rate (%) in the present invention is based on JIS synthetic fiber filament bulky processed yarn L1090.5.10.Hot water shrinkage rate B method. In addition, the relaxation rate OF (%) during the relaxation heat treatment is the speed of the entrance roller in the crimp development process V ₁ (m/min),
Determine from the exit roller speed V ₂ (m/min) as V ₁ −V ₂ /V ₁ × 100. Hereinafter, the present invention will be specifically explained in Examples. In addition, in the examples, the expansion/contraction rate is after hot water treatment.
JIS synthetic fiber filament bulky yarn L1090.5.7.
This is a value measured by the stretchability C method. Example 1 Two 50d/18f undrawn yarns obtained by composite spinning polyethylene terephthalate with [η] of 1.31 and polyethylene terephthalate with [η] of 1.38 in a 1:1 ratio to form a dorsal-ventral structure. A mixed fiber yarn was obtained by drawing under the following conditions. That is, one undrawn yarn mentioned above is drawn at a stretching ratio of 2.65 times, a hot roller temperature of 90°C, and a hot plate temperature of 160°C to form yarn A. At the same time, another undrawn yarn is drawn without using a hot plate. Except for this, the drawing was carried out in the same manner as above, and yarn B was mixed with yarn B, yarn A was mixed with yarn B, and the yarn was wound into a pirn using a draw twister to obtain a mixed yarn of 75d/36f. Yarn A has a number of crimps of 21/2.5 after boiling water treatment.
cm, and the hot water shrinkage rate was 6.2%, and the hot water shrinkage rate of Yarn B was 12.1%. In addition, the hot water shrinkage rate of the blended yarn was 11.6%. The above blended yarn was heated to
140℃ relaxation rate 20%, delivery speed after crimp onset 70
It was subjected to relaxation heat treatment at m/min and rolled into cheese. The obtained yarn was extremely bulky and had a spun-like feel, and had an elongation rate of 24.5%. Example 2 Polyethylene terephthalate with [η] of 1.31 and polyethylene terephthalate with [η] of 1.41 were spun into a dorsal-ventral structure at a ratio of 1:1.
A 50d/18f undrawn yarn was drawn at a draw ratio of 2.65 times, a hot roller temperature of 90°C, and a hot plate temperature of 160°C to obtain yarn A, and at the same time polyethylene terephthalate with [η] of 1.41 was spun.
50d/18f undrawn yarn is drawn in the same manner as above except that the hot plate is not used to form yarn B, yarn A and yarn B are mixed, and wound into a pirn using a draw twister to form 75d/18f. A 36f mixed yarn was obtained. Yarn A had a number of crimps of 36/2.5 cm after being treated with boiling water. The hot water shrinkage rates of yarn A, yarn B, and mixed yarn were 7.3%, 14.6%, and 13.5%, respectively. The obtained yarn was extremely bulky and had a spun-like feel, and had an elongation rate of 10.9%. Comparative Example 1 Table 1 shows the relationship between the number of crimps and the bulkiness of a dorsal-ventral composite yarn (yarn A). According to Table 1, it is clear that high bulkiness can be obtained when the number of crimps of the composite yarn after boiling water treatment is 15 crimps/2.5 cm or more. It should be noted that, as yarn B, a composite yarn having the same structure as yarn A was used.

[Table] [Note] PET: Polyethylene terephthalate 〇: Very good △: Good ×: Poor Comparative example 2 The undrawn yarn used in Example 1 was stretched to produce yarn A and yarn with various hot water shrinkage rates. B and the relaxation rate OF
(%) Table 2 shows the results when bulky mixed yarns were made by varying the heat treatment temperature T (℃) and the hot water shrinkage rates S ₁ (%) and S ₂ (%) of yarn A and yarn B. Shown below.

【table】

[Table] △: Good overall evaluation
Note that a blank column indicates a poor overall evaluation.

Claims (1)

[Claims] 1. The number of crimps is 15/2.5cm when heat treated for 10 minutes under a load of 1.7×10 ^-4 g/d in boiling water.
Latent crimpable synthetic fiber yarn A that exhibits crimps of
and a thermoplastic synthetic fiber yarn B having a hot water shrinkage rate of 10% to 20% and a hot water shrinkage rate 5% to 10% higher than that of the yarn A, as shown below (1). ) A method for producing a bulky mixed fiber yarn, characterized by carrying out relaxation heat treatment under conditions that satisfy the following formula: However, OF: Relaxation rate (%) T: Heat treatment temperature (℃) 100≦T≦180 S ₁ : Hot water shrinkage rate of yarn A (%) S ₂ : Hot water shrinkage rate of yarn B (%)